OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
MATHEMATICA
a = {}; Do[k = 1; While[ Count[ IntegerDigits[4^k], 6] != n, k++ ]; a = Append[a, k], {n, 0, 50} ]; a
Log[4, #]&/@Table[First[Select[4^Range[900], DigitCount[#, 10, 6]==n&]], {n, 0, 60}] (* Harvey P. Dale, May 15 2011 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Robert G. Wilson v, Aug 10 2001
EXTENSIONS
Name corrected by Jon E. Schoenfield, Jun 26 2018
STATUS
approved